It is a type of fuel source for a fire, and is also used to repair heavy hammers.

Fir firewood has an estimated fire duration of 1 hour and 30 minutes, so, with 90 min/kg it has a worse burning time per weight than cedar firewood, which gives 120 min/kg.

Fire firewood can be harvested from fir tree limbs using a hatchet or hacksaw. A small fir limb will give 3 pieces of fir, and a large fir limb will give 4. Fir firewood can also be found inside some buildings as loot.